#include<stdio.h>
 int main()
 {  int x,y;
     printf("input x");
	 scanf("%d",&x);
	 if(x<1)
		 y=x;
	 else if (x<10)
         y=2*x-1;
	 else  y=3*x-11;
	   printf("y=%d",y);
 return 0;
 }
